U.S. patent number 9,458,309 [Application Number 14/674,243] was granted by the patent office on 2016-10-04 for molding material and liquid ejection flow path member using the same.
This patent grant is currently assigned to CANON KABUSHIKI KAISHA. The grantee listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Isao Imamura, Shogo Kawamura, Yoshiyuki Shino.
United States Patent |
9,458,309 |
Imamura , et al. |
October 4, 2016 |
Molding material and liquid ejection flow path member using the
same
Abstract
The invention provides a molding material including a liquid
epoxy resin composition containing an epoxy resin, a curing agent
or a curing catalyst, a filler, a thixotropy-imparting agent, and a
wetting dispersant.
Inventors: |
Imamura; Isao (Kawasaki,
JP), Shino; Yoshiyuki (Yokohama, JP),
Kawamura; Shogo (Kawasaki, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
N/A |
JP |
|
|
Assignee: |
CANON KABUSHIKI KAISHA (Tokyo,
JP)
|
Family
ID: |
54334142 |
Appl.
No.: |
14/674,243 |
Filed: |
March 31, 2015 |
Prior Publication Data
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Document
Identifier |
Publication Date |
|
US 20150307689 A1 |
Oct 29, 2015 |
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Foreign Application Priority Data
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Apr 23, 2014 [JP] |
|
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2014-088978 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08K
3/22 (20130101); C08K 5/21 (20130101); C08K
3/36 (20130101); B41J 2/155 (20130101); C08K
5/5435 (20130101); C08K 5/521 (20130101); C08K
3/36 (20130101); C08L 63/00 (20130101); C08K
5/5435 (20130101); C08L 63/00 (20130101); C08K
5/21 (20130101); C08L 63/00 (20130101); C08K
3/22 (20130101); C08L 67/03 (20130101); C08K
5/521 (20130101); C08L 63/00 (20130101); C08K
2003/2227 (20130101); B41J 2002/14306 (20130101); B41J
2202/20 (20130101); B41J 2/14145 (20130101); B41J
2002/14419 (20130101); B41J 2202/03 (20130101) |
Current International
Class: |
C08K
5/521 (20060101); C08K 3/36 (20060101); C08K
3/22 (20060101); C08K 5/21 (20060101); C08K
5/5435 (20060101); B41J 2/14 (20060101) |
Field of
Search: |
;347/20 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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5-24192 |
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Feb 1993 |
|
JP |
|
2009-155370 |
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Jul 2009 |
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JP |
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2011-173970 |
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Sep 2011 |
|
JP |
|
Primary Examiner: Shah; Manish S
Assistant Examiner: Ameh; Yaovi M
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper &
Scinto
Claims
What is claimed is:
1. A liquid ejection head including a liquid ejection flow path
member, the liquid ejection flow path member comprising a cured
product of a molding material comprising a liquid epoxy resin
composition containing an epoxy resin, a curing agent or a curing
catalyst, a filler, a thixotropy-imparting agent, and a wetting
dispersant, wherein a content of the filler in the molding material
is at least 70% by volume, and wherein a content of the liquid
epoxy resin in the molding material is from 1% by volume to 30% by
volume.
2. The liquid ejection head according to claim 1, wherein the
thixotropy-imparting agent is urea-urethane.
3. The liquid ejection head according to claim 1, wherein the
wetting dispersant is a phosphate ester salt.
4. The liquid ejection head according to claim 1, wherein the
liquid epoxy resin composition contains trialkyltetrahydrophthalic
anhydride as the curing agent.
5. The liquid ejection head according to claim 1, wherein the
liquid epoxy resin composition contains a liquid imidazole as the
curing agent.
6. The liquid ejection head according to claim 1, wherein the epoxy
resin has a dicyclopentadiene skeleton.
7. The liquid ejection head according to claim 1, wherein the
liquid epoxy resin composition contains a silane coupling
agent.
8. The liquid ejection head according to claim 1, further
comprising a recording element substrate having an ejection orifice
and a support member for supporting the recording element
substrate, wherein the liquid ejection flow path member comprises
the support member, and wherein the support member comprises the
cured product.
9. The liquid ejection head according to claim 1, wherein the
content of the filler is at least 79% by volume.
10. A liquid ejection head including a liquid ejection flow path
member, the liquid ejection flow path member comprising a cured
product of a molding material comprising a liquid epoxy resin
composition containing an epoxy resin, a curing agent or a curing
catalyst, a filler, a thixotropy-imparting agent, and a wetting
dispersant, wherein a content of the filler in the molding material
is at least 70% by volume, and wherein a content of the liquid
epoxy resin in the molding material is from 0.01% by volume to 0.5%
by volume.
11. The liquid ejection head according to claim 10, wherein the
thixotropy-imparting agent is urea-urethane.
12. The liquid ejection head according to claim 10, wherein the
wetting dispersant is a phosphate ester salt.
13. The liquid ejection head according to claim 10, wherein the
liquid epoxy resin composition contains trialkyltetrahydrophthalic
anhydride as the curing agent.
14. The liquid ejection head according to claim 10, wherein the
liquid epoxy resin composition contains a liquid imidazole as the
curing agent.
15. The liquid ejection head according to claim 10, wherein the
epoxy resin has a dicyclopentadiene skeleton.
16. The liquid ejection head according to claim 10, wherein the
liquid epoxy resin composition contains a silane coupling
agent.
17. The liquid ejection head according to claim 10, further
comprising a recording element substrate having an ejection orifice
and a support member for supporting the recording element
substrate, wherein the liquid ejection flow path member comprises
the support member, and wherein the support member comprises the
cured product.
18. The liquid ejection head according to claim 10, wherein the
content of the filler is at least 79% by volume.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a molding material and a liquid
ejection flow path member using the same.
2. Description of the Related Art
An ink jet recording apparatus involves relatively low running
costs, is capable of being miniaturized, and can easily be adapted
to color image recording with a plurality of inks, and so it is
widely used in, for example, computer-related output equipment as a
commercial product.
In recent years, there has been a demand for developing an ink jet
recording head having a longer recording width so as to make it
possible to record a high-definition image at higher speed.
Specifically, an ink jet recording head having a recording width of
from 4 inches (10.2 cm) to 12 inches (30.5 cm) in length is
required. As a method for realizing an ink jet recording head
having a long recording width, for example, Japanese Patent
Application Laid-Open No. H05-24192 proposes a method of arranging
a plurality of recording element substrates each having a moderate
length on a support member to realize an ink jet recording head
having a long recoding width as a whole.
In the method described in Japanese Patent Application Laid-Open
No. H05-24192, the support member is required to have a high
flatness and a low coefficient of linear expansion to cause no
stress to a substrate such as Si. In addition, the support member
is required to have high ink resistance. The reason for this is
that if a material of the support member is dissolved in an ink,
ejection performance is lowered, and deposit may occur in some
cases to block an ejection orifice. An example of a representative
material having these properties includes alumina. However, it is
expensive to form a large-sized part with alumina. On the other
hand, if a resin molding material disclosed in Japanese Patent
Application Laid-Open No. 2011-173970 or No. 2009-155370 is used to
cheaply produce the support member, the coefficient of linear
expansion and ink resistance thereof are not always sufficient.
In addition, if an epoxy resin is used as a material of the support
member in view of chemical resistance, it is necessary to increase
the addition amount of filler for achieving a coefficient of linear
expansion comparable with alumina. However, if the addition amount
of the filler is increased, a mixture thereof becomes finely
granular or powdery such as powder, and so it is impossible to
uniformly mix the epoxy resin with the filler. On the other hand,
even if the amount of the filler to be added is reduced to
uniformly mix such materials, the epoxy resin expands upon
extrusion under heating upon transfer molding, and the viscosity of
the epoxy resin is lowered, and so surface roughening in which the
epoxy resin is separated from the filler occurs, and surface
accuracy cannot be ensured.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a molding
material in which an epoxy resin is uniformly mixed with a filler
even when the addition amount of the filler is increased and with
which the epoxy resin is not separated from the filler upon
molding.
In order to achieve the above object, the present invention
provides a molding material comprising a liquid epoxy resin
composition containing an epoxy resin, a curing agent or a curing
catalyst, a filler, a thixotropy-imparting agent, and a wetting
dispersant.
The present invention also provides a liquid ejection flow path
member comprising a cured product of the molding material according
to the present invention.
Further features of the present invention will become apparent from
the following description of exemplary embodiments with reference
to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B illustrate an example of a liquid ejection head
provided with a support member containing a cured product of the
molding material according to the present invention, in which FIG.
1A illustrates a side elevational view and a bottom view, and FIG.
1B illustrates an exploded perspective view.
DESCRIPTION OF THE EMBODIMENTS
Preferred embodiments of the present invention will now be
described in detail in accordance with the accompanying
drawings.
The molding material according to the present invention contains a
liquid epoxy resin composition containing an epoxy resin, a curing
agent or a curing catalyst, a filler, a thixotropy-imparting agent,
and a wetting dispersant. In the molding material according to the
present invention, the liquid epoxy resin composition is used as a
resin component, and the wetting dispersant is added, whereby the
resulting mixture becomes clayish even when the composition is
highly filled with the filler, and so the epoxy resin is uniformly
mixed with the filler. In addition, the thixotropy-imparting agent
is added, whereby separation of the resin component from the filler
upon molding can be inhibited. The molding material according to
the present invention can be favorably used as a material of a
support member for supporting a recording element substrate in a
full-line type recording head of, in particular, a liquid ejection
system which will be described subsequently.
Liquid Epoxy Resin Composition
The liquid epoxy resin composition contains an epoxy resin, a
curing agent or a curing catalyst and has such a feature that it is
liquid at ordinary temperature (15 to 35.degree. C.) The liquid
epoxy resin composition may contain a curing accelerator and a
silane coupling agent as needed in addition to the epoxy resin and
the curing agent or the curing catalyst. For example, the liquid
epoxy resin composition may be composed of the epoxy resin, the
curing agent and the silane coupling agent. The respective
components may be solid so far as the prepared epoxy resin
composition is liquid. A flowable liquid epoxy resin composition is
used as the epoxy resin composition, whereby the composition can be
highly filled with the filler, and the filler can be sufficiently
covered with the resin component. In addition, the liquid epoxy
resin composition is used, whereby the epoxy resin is uniformly
mixed with the curing agent or the curing catalyst at a molecular
level unlike a molding material prepared by mixing a solid material
to make the resulting mixture bulky with a pelletizing agent such
as wax. Therefore, the molding material according to the present
invention shows no ununiformity of the components, and a cured
product thereof has excellent chemical resistance. The content of
the liquid epoxy resin composition in the molding material is
favorably 30% by volume or less, more favorably 25% by volume or
less. In addition, the content is favorably 1% by volume or more,
more favorably 5% by volume or more.
Examples of the epoxy resin include bisphenol A type epoxy resins,
bisphenol F type epoxy resins, bisphenol AD type epoxy resins,
compounds obtained by adding an alkylene oxide to these epoxy
resins, epoxy novolak resins, glycidyl ether type epoxy resins such
as bisphenol A novolak diglycidyl ether, bisphenol F novolak
diglycidyl ether, and alicyclic epoxy resins. A solid epoxy resin
may also be used in addition to the liquid epoxy resin so far as
the prepared epoxy resin composition is liquid. Examples of the
solid epoxy resin include epoxy resins having a biphenyl skeleton,
a naphthalene skeleton, a cresol novolak skeleton, trisphenol
methane skeleton, dicyclopentadiene skeleton and a phenol
biphenylene skeleton. Among these, an epoxy resin having a
dicyclopentadiene skeleton is favorably used from the viewpoint of
dimensional change due to moisture absorption or water absorption.
These epoxy resins may be used either singly or in any combination
thereof. The content of the epoxy resin in the liquid epoxy resin
composition is favorably 30% by mass or more and 95% by mass or
less, more favorably 40% by mass or more and 95% by mass or
less.
For example, an amine, a polyamide, an acid anhydride, imidazole or
phenol may be used as the curing agent. In addition, a compound
obtained by adding an epoxy resin to the above-mentioned compound
to improve the pot life and reactivity thereof may also be used.
Further, a low viscosity compound having latency is favorable as
the curing agent. Examples of the curing agent include acid
anhydrides such as tetrahydrophthalic anhydride,
methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride,
methylhexahydrophthalic anhydride, methylnadic anhydride,
hydrogenated methylnadic anhydride and trialkyltetrahydrophthalic
anhydride; and imidazoles such as 2-ethyl-4-methylimidazole and
1-(2-cyanoethyl)-2-ethyl-4-methylimidazole. In addition, a solid
curing agent may also be used as the curing agent in addition to
the liquid curing agent so far as the resulting epoxy resin
composition is liquid. Examples of the solid curing agent include
phenolic curing agents such as xylylene novolak, biphenyl novolak
and dicyclopentadiene phenol novolak. Among these,
trialkyltetrahydrophthalic anhydride is favorably used as the
curing agent from the viewpoint of dimensional change due to
moisture absorption or water absorption. In addition, a liquid
imidazole is favorably used as the curing agent from the viewpoints
of latency and reactivity. Incidentally, the liquid imidazole means
an imidazole that is liquid at ordinary temperature (15 to
35.degree. C.). Examples of the liquid imidazole include
1,2-dimethylimidazole, 2-ethyl-4-methylimidazole and
1-benzyl-2-methylimidazole. These curing agents may be used either
singly or in any combination thereof.
Examples of the curing catalyst include tertiary amines, boron
trifluoride-amine complexes and cationic polymerization catalysts.
These curing catalysts may be used either singly or in any
combination thereof.
Examples of the curing accelerator include imidazole,
tetraethylammonium bromide, tetraphenyl-phosphonium bromide,
1,8-diaza-bicyclo-(5,4,0)-undecene-7 and 2-ethylhexanoic acid
salts. These curing accelerators may be used either singly or in
any combination thereof.
The liquid epoxy resin composition favorably contains a silane
coupling agent from the viewpoint of adhesion to the filler.
Examples of the silane coupling agent include
.gamma.-glycidoxypropyltrimethoxysilane,
.beta.-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,
.gamma.-mercaptopropyl-triethoxysilane and
.gamma.-aminopropyltrimethoxysilane. These silane coupling agents
may be used either singly or in any combination thereof. The
content of the silane coupling agent in the liquid epoxy resin
composition is favorably 1% by volume or more and 10% by volume or
less, more favorably 2% by volume or more and 6% by volume or less.
Incidentally, since the specific gravity of the silane coupling
agent is about 1, the content of the silane coupling agent in the
liquid epoxy resin composition is favorably 1% by mass or more and
10% by mass or less, more favorably 2% by mass or more and 6% by
mass or less. In addition, a titanate-based or aluminate-based
coupling agent may also be used.
Filler
Examples of the filler include glass, titanium oxide, alumina,
aluminum hydroxide, magnesium hydroxide, talc, mica and silica.
Among these, fused silica with low coefficient of linear expansion
is favorable as the filler. The shape of the filler is favorably
spherical from the viewpoint of increasing a filling rate. In
addition, a filler different in particle size is favorably
contained from such a viewpoint that closest filling can be
conducted. For example, when two fillers different in particle size
are contained, the ratio between the fillers different in particle
size in these fillers is favorably 9:1 to 6:4 in terms of the
volume ratio of a large particle size filler to a small particle
size filler. In addition, plural kinds of fillers may also be mixed
and used according to requested properties. For example, when the
molding material according to the present invention is used in a
container for a strong alkaline solution, alumina having high
chemical resistance is used in combination as a filler, good
chemical resistance is achieved.
The content of the filler in the molding material is favorably 70%
by volume or more, more favorably 79% by volume or more from such a
viewpoint that the effect of the present invention can be more
successfully developed though it may vary according to the kind of
the filler and the viscosity of the epoxy resin. For example, when
fused quartz is used as the filler, the content thereof is
favorably 79% by volume or more.
Thixotropy-Imparting Agent
Examples of the thixotropy-imparting agent include inorganic fine
materials such as fused silica and modified urethanes. The
thixotropy-imparting agent is favorably liquid at ordinary
temperature (15 to 35.degree. C.) from such a viewpoint that the
thixotropy can be imparted without increasing the viscosity so
much. Examples of the liquid thixotropy-imparting agent include
modified urethanes. In particular, a compound having a modified
urethane skeleton is good in compatibility with epoxy, and so a
cured product thereof is less elutable in a liquid such as an ink.
Among the modified urethanes, urea-urethane is favorable. These
thixotropy-imparting agents may be used either singly or in any
combination thereof.
The content of the thixotropy-imparting agent in the molding
material is favorably 0.01% by volume or more and 0.5% by volume or
less, more favorably 0.04% by volume or more and 0.2% by volume or
less though it may vary according to the kinds of the filler and
the epoxy resin. The thixotropy-imparting agent is contained in a
proportion of 0.01% by volume or more to the filler, whereby a
sufficient effect can be achieved. In addition, the
thixotropy-imparting agent is contained in a proportion of 0.2% by
volume or less to the filler, whereby the lowering of flowability
due to increase of viscosity when the thixotropy-imparting agent is
an inorganic fine material can be inhibited. In addition, when the
thixotropy-imparting agent is a liquid thixotropy-imparting agent
which does not participate in reaction, elution and/or separation
of the thixotropy-imparting agent after cured can be inhibited.
Wetting Dispersant
A phosphate ester salt or an alkylammonium salt is favorable as the
wetting dispersant. Examples of commercially available products
thereof include DISPERBYK-142, DISPERBYK-145, DISPERBYK-164 and
BYK-9076 (all, trade names, products of BYK-Chemie GmbH), and
DISPARLON 1860 (trade name, product of Kusumoto Chemicals, Ltd.).
These wetting dispersants may be used either singly or in any
combination thereof.
The content of the wetting dispersant in the molding material is
favorably 0.01% by volume or more and 0.5% by volume or less, more
favorably 0.04% by volume or more and 0.2% by volume or less though
it may vary according to the kinds of the filler and the epoxy
resin. The wetting dispersant is contained in a proportion of 0.01%
by volume or more to the filler, whereby a sufficient effect is
achieved. In addition, the wetting dispersant is contained in a
proportion of 0.5% by volume or less to the filler, whereby the
wetting dispersant does not participate in reaction, and elution
and/or separation of the wetting dispersant after cured can be
prevented.
The molding material according to the present invention may
suitably contain a diluent or another additive in addition to the
above-described components.
Since the molding material according to the present invention has a
low coefficient of linear expansion, is excellent in moldability
and is less elutable in a liquid such as an ink, it is suitably
used as a support member 1200 of such a liquid ejection head having
a wide recording width as illustrated in, for example, FIG. 1B.
FIG. 1A illustrates a side elevational view and a bottom view of
the liquid ejection head 1000, and FIG. 1B is an exploded
perspective view illustrating parts constructing the liquid
ejection head 1000 illustrated in FIG. 1A. In the liquid ejection
head 1000, an ejection orifice array is formed over a range capable
of covering the overall width of a sheet which may be used, and so
the liquid ejection head is a full-line type recording head of a
liquid ejection system capable of conducting large-width recording
without scanning the liquid ejection head 1000.
The liquid ejection head 1000 has a recording element substrate
1100 formed of Si and a liquid supply slit 1210, a support member
1200 for supporting the recording element substrate, an electric
wiring board 1300 for electrically connecting the recording element
substrate to a recording apparatus and a liquid storage portion
1510 and is provided with a liquid supply member 1500 joined to the
support member 1200. A plurality of the recording element
substrates 1100 each have an ejection orifice 1105 and are arranged
on a principal plane 1200a of the support member 1200 with a high
precision in a direction (Y-direction) intersecting a direction of
conveying a recording medium (X-direction). In FIG. 1B, the
plurality of the recording element substrates 1100 are alternately
arranged in two rows in such a manner that the end portions 1109 of
the ejection orifice arrays overlap with each other. The liquid
supply member 1500 is arranged on a plane 1200b opposing the
principal plane 1200a. The electric wiring board 1300 is provided
with an electrode terminal 1320 and an opening 1330.
The support member 1200 is required to have high resistance to a
liquid such as an ink because it forms a part of a flow path. For
example, when a material of the support member is dissolved in the
liquid such as the ink even in an amount of several ppm levels, the
liquid such as the ink evaporates in the vicinity of the ejection
orifice, and deposits adhere to the vicinity of the ejection
orifice. Therefore, dot misalignment of ejected droplets may occur
in some cases to cause defective printing. In addition, since the
support member 1200 is bonded to the recording element substrate
1100 formed of Si with, for example, an adhesive, it is favorable
that the coefficient of linear expansion of the support member 1200
is lower, and so the support member is required to have high
dimensional accuracy. Since the molding member according to the
present invention has a low coefficient of linear expansion, is
excellent in moldability and is little dissolved in the liquid such
as the ink, a cured product of the molding material according to
the present invention is favorably used as a liquid ejection flow
path member such as a support member 1200. Examples of the liquid
ejection flow path member include an ink jet flow path member.
The molding material according to the present invention may be
prepared at a temperature of, for example, from 15.degree. C. to
35.degree. C. by kneading the filler and the like with the liquid
epoxy resin composition. Since the kneading may be conducted in
such an ordinary temperature atmosphere, an epoxy resin composition
with high reactivity, which has heretofore not been used, can be
used.
Since the molding material according to the present invention is
clayish at ordinary temperature, any amount thereof may be simply
weighed out. In addition, since a molding material is pelletized in
usual transfer molding, it is required to be preheated by, for
example, microwave. However, the molding material according to the
present invention can be molded without conducting the preheating.
Further, since the molding material according to the present
invention is low in melt viscosity and high in flowability upon
molding, it can be used for molding of a complicated, precise and
large part.
In the present invention, the liquid epoxy resin composition and
the wetting dispersant are used, whereby the surface of the filler
can be covered with the epoxy resin without developing a pinhole,
so that no dissolution of the filler component is observed.
When, for example, a powdery curing agent is melted by heating and
caused to react with the molding material according to the present
invention, a portion where the amount of the curing agent is large
and a portion where the amount is small are caused when locally
viewed. However, since the epoxy resin composition is liquid and
uniformly dissolved, reaction can be completed. Therefore, the
molding material according to the present invention is excellent in
chemical resistance, and its dissolution in a liquid such as an ink
is scarcely observed.
Since the molding material according to the present invention has
excellent properties as described above, it can be used in a part
for which elution of a material from the part needs to be avoided.
The molding material according to the present invention is suitably
used in not only the liquid ejection flow path member, but also a
member of, for example, a water purifier or medical equipment.
EXAMPLES
Molding materials were evaluated as to the following items.
Moldability
Transfer molding was conducted by means of MF-0 (trade name,
manufactured by MARUSHICHI ENGINEERING CO., LTD.) under the
following conditions to mold a molding material into a strip
specimen (70.times.10.times.3 mm (thickness)), thereby confirming
the moldability of the molding material. Incidentally, a mold is an
assembling type, and so a molded article is taken out by separating
and disassembling the mold.
Injection pressure: 50 kgf/cm.sup.2;
Injection speed: 5 cm/s;
Cure time: 5 minutes; and
Six parts per one shot.
A cured product obtained by further heat-curing the molded article
obtained by the above method for 1.5 hours at 180.degree. C. was
used to evaluate it as to ink absorption rate, coefficient of
linear expansion, glass transition temperature, elastic modulus and
tensile strength whose evaluation methods will be shown below.
Ink Absorption Rate
The cured product was immersed for 1 hour in a transparent ink for
distribution (product of Canon Inc.) to measure the mass change
before and after the immersion. The change rate of the mass was
regarded as an ink absorption rate.
Glass Transition Temperature (Tg) and Coefficient of Linear
Expansion
TMA SS6100 (trade name, manufactured by SII Nano Technology Inc.)
was used to measure a transition point of linear expansion, and
thus the temperature at this point was regarded as the class
transition temperature (Tg) to determine al (coefficient of linear
expansion at the glass transition temperature or lower).
Elastic Modulus
DMS (viscoelasticity measuring device; trade name: DMS 6100,
manufactured by SII Nano Technology Inc.) was used to measure the
elastic modulus under conditions of 25.degree. C. and 10 KHz.
Tensile Strength
Tensile strength was determined by a 5582 type universal material
testing machine (manufactured by Instron Co.) in accordance with
ASTM D638.
Example 1
A molding material of the formulation shown in Table 1 was
prepared. Specifically, after a liquid epoxy resin composition, a
thixotropy-imparting agent and a wetting dispersant were mixed, the
resultant mixture was stirred while gradually adding a filler into
the mixture. The mixing of the respective materials was conducted
by using a planetary mixer while controlling the temperature to
25.degree. C. Thereafter, the mixture was kneaded by a triple roll
mill so as not to leave aggregates of the filler, thereby obtaining
the molding material. The molding material was subjected to the
above-described evaluations. The results are shown in Table 1.
Examples 2 to 9, and Comparative Examples 1 to 10
Molding materials were prepared in the same manner as Example 1
except that the formulation of the molding material was changed to
the formulations shown in Tables 1 and 2 to make the evaluations.
Results are shown in Tables 1 and 2.
TABLE-US-00001 TABLE 1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7
Ex. 8 Ex. 9 Liquid Epoxy resin jER Cure 828EL 95 95 95 95 95 95 95
-- -- epoxy resin HP-7200L -- -- -- -- -- -- -- 95 95 composition
Curing agent jER Cure YH-307 110 110 -- -- -- -- -- 100 100 (part
by jER Cure EMI24 0.5 0.5 4 4 4 4 4 0.5 0.5 mass) Silane coupling
A-187 -- -- 5 5 5 5 5 5 5 agent A-186 5 5 -- -- -- -- -- -- --
Thixotropy-imparting agent BYK-410 0.5 0.5 -- 0.5 -- 0.5 0.5 1 1
(part by mass) BYK-411 -- -- 0.5 -- -- -- -- -- -- Aerosil 200 --
-- -- -- 2 -- -- -- -- Wetting dispersant (part by mass)
DISPERBYK-145 0.5 0.5 0.5 0.5 0.5 0.5 0.5 1 1 Filler (part by mass)
FB-950 1700 200 800 800 800 -- 320 1600 -- FB-5D 100 1000 100 100
100 -- 20 200 -- DMA-20 -- -- -- -- -- 900 730 -- 1800 DMA-05A --
-- -- -- -- 100 80 -- 200 Formulation Liquid epoxy resin
composition 10.46 14.90 10.35 10.35 10.33 9.40 8.29 10.01 9.10 of
molding Thixotropy-imparting agent 0.02 0.04 0.05 0.05 0.20 0.05
0.04 0.05 0.05 material Wetting dispersant 0.02 0.04 0.05 0.05 0.05
0.05 0.04 0.05 0.05 (% by mass) Filler 89.50 85.02 89.55 89.55
89.42 90.50 91.63 89.89 90.80 Formulation Liquid epoxy resin
composition 20.44 27.81 20.23 20.23 20.17 28.78 18.94 19.64 28.03
of molding Thixotropy-imparting agent 0.05 0.07 0.10 0.10 0.10 0.14
0.09 0.10 0.14 material Wetting dispersant 0.05 0.07 0.10 0.10 0.10
0.14 0.09 0.10 0.14 (% by volume) Filler 79.46 72.06 79.58 79.58
79.34 70.95 80.88 80.16 71.69- State Clayish Clayish Clayish
Clayish Clayish Clayish Clayish Clayish Clay- ish Ink absorption
rate (%) 0.30 0.50 0.31 0.31 0.31 0.25 0.28 0.21 0.18 Coefficient
of linear expansion (ppm/.degree. C.) 7.2 10 6.5 6.5 6.5 18 9.8 6.0
18 Tg (.degree. C.) 80 80 138 138 138 140 139 115 114 Elastic
modulus (GPa) 16 14 15 15 15 19 18 19 18 Tensile strength (MPa) 70
70 68 68 68 50 55 70 50 Moldability Good Good Good Good Good Good
Good Good Good
TABLE-US-00002 TABLE 2 Comp. Comp. Comp. Comp. Comp. Comp. Comp.
Comp. Comp. Comp. Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8
Ex. 9 Ex. 10 Epoxy Epoxy resin jER Cure 828EL 95 95 95 95 95 95 95
95 95 -- resin HP-7200L -- -- -- -- -- -- -- -- -- 95 composition
Curing agent jER Cure YH-307 -- -- -- -- -- -- -- -- -- -- (part by
jER Cure EMI24 4 4 4 4 4 4 4 4 4 4 mass) Silane coupling A-187 5 5
5 5 5 5 5 5 5 5 agent A-186 -- -- -- -- -- -- -- -- -- -- State
Liq- Liq- Liq- Liq- Liq- Liq- Liq- Liq- Liq- Sol- uid uid uid uid
uid uid uid uid uid id Thixotropy-imparting BYK-410 -- -- 0.5 -- --
-- -- 2 5 -- agent (part by mass) BYK-411 -- -- -- -- -- -- -- --
-- 0.5 Aerosil 200 -- -- -- -- -- 2 5 -- -- -- Wetting dispersant
DISPERBYK-145 -- 0.5 -- 2 5 -- -- -- -- 0.5 (part by mass) Filler
(part by mass) FB-950 800 800 800 800 800 800 800 800 800 800 FB-5D
100 100 100 100 100 100 100 100 100 100 DMA-20 -- -- -- -- -- -- --
-- -- -- DMA-05A -- -- -- -- -- -- -- -- -- -- Formulation Epoxy
resin composition 10.36 10.35 10.35 10.34 10.30 10.34 10.30 10.34
10.30 10.35 of molding Thixotropy-imparting agent 0 0 0.05 0 0 0.20
0.50 0.20 0.50 0.05 material Wetting dispersant 0 0.05 0 0.20 0.50
0 0 0 0 0.05 (% by mass) Filler 89.64 89.60 89.60 89.46 89.20 89.46
89.20 89.46 89.20 8- 9.55 Formulation Epoxy resin composition 20.27
20.24 20.24 20.19 20.06 20.19 20.06 20.19 20.06 20.23 of molding
Thixotropy-imparting agent 0 0 0.10 0 0 0.39 0.97 0.39 0.97 0.10
material Wetting dispersant 0 0.10 0 0.39 0.97 0 0 0 0 0.10 (% by
volume) Filler 79.73 79.66 79.66 79.42 78.97 79.42 78.97 79.42
78.97- 79.57 State Gran- Clay- Gran- Clay- Clay- Gran- Pow- Gran-
Gran- Pow- ular ish ular ish ish ular dery ular ular dery Ink
absorption rate (%) Not measured Coefficient of linear expansion
(ppm/.degree. C.) Tg (.degree. C.) Elastic modulus (GPa) Tensile
strength (MPa) Moldability *1 *2 *1 *2 *3 *1 *4 *1 *5 *1
iER Cure 828EL: Trade name, bisphenol type epoxy resin (liquid),
produce of Mitsubishi Chemical Corporation; HP-7200L: Trae name,
dicyclopentadiene type epoxy resin (solid), product of DIC
Corporation; iER Cure YH-307L: Trade name,
trialkyltetrahydrophthalic anhydride (liquid), produce of
Mitsubishi Chemical Corporation; iER Cure EM124: Trade name,
2-ethyl-4-methylimidazole (liquid), produce of Mitsubishi Chemical
Corporation; A-187: Trade name,
.gamma.-glycidoxypropyltrimethoxysilane, product of Momentive
Performance Material Inc.; A-186: Trade name,
.beta.-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, product of
Momentive Performance Material Inc.; BYK-410: Trade name,
urea-urethane, product of BYK-Chemie GmbH; BYK-411: Trade name,
urea-urethane, product of BYK-Chemie GmbH; Aerosil 200: Trade name,
product of NIPPON AEROSIL CO., LTD.; DISPERBYK-145: Trade name,
phosphate salt, product of BYK-Chemie GmbH; FB-950: Trade name,
spherical fused silica having an average particle size of 24 atm,
product of DENKI KAGAKU KOGYO KABUSHIKI KAISHA; FB-5D: Trade name,
spherical fused silica having average particle size of 5 .mu.m,
product of DENKI KAGAKU KOGYO KABUSHIKI KAISHA; DMA-20: trade name,
spherical alumina having an average particle size of 20 .mu.m,
product of DENKI KAGAKU KOGYO KABUSHIKI KAISHA; DMA-05A: trade
name, spherical alumina having an average particle size of 20
.mu.m, product of DENKI KAGAKU KOGYO KABUSHIKI KAISHA.
1: Short shot and numerous voids;
2: Separation between the resin and the filler;
3: Separation among the resin, the wetting dispersant and the
filler;
4: Short shot (almost no flow) and numerous voids;
5: Short shot, bubbly, and bleeding of the thixotropy-imparting
agent.
In Examples 1 to 9, the molding materials with excellent
moldability and physical properties were obtained. In Examples 1
and 2, the coefficient of linear expansion was adjusted by changing
the mixing ratio between the fillers different in particle size.
When the particle size of a filler is small, its specific surface
area becomes large, and so its filling amount becomes small. In
Example 2, the proportion of a filler having a small particle size
is increased, thereby preparing a clayish molding material which
can be easily used. In Examples 3 to 5, the amount of the
thixotropy-imparting agent was changed. However, all the resultants
molding materials exhibited good moldability. In Example 6, alumina
was used as the filler. In Example 7, a part of the filler in
Example 6 was changed to fused silica. As described above, plural
kinds of fillers may also be used in combination. In Examples 8 and
9, the solid epoxy resin was used. However, a liquid epoxy resin
composition was obtained after the curing agent and the silane
coupling agent were mixed. Accordingly, the kneading of the filler
could be successfully conducted.
On the other hand, in Comparative Examples 1 to 10, molding could
not successfully conducted as shown in Table 2, and so the
evaluations of the respective physical properties could not made.
The molding material of Comparative Example 1 contains neither the
thixotropy-imparting agent nor the wetting dispersant. Since the
wetting dispersant is not contained in Comparative Example 1, the
filler could not be uniformly wetted with the liquid epoxy resin
composition, and so the resultant molding material becomes
granular. When it was attempted to disperse the filler by lowering
the viscosity of the molding material by heating it, the reaction
proceeded to lower the moldability of the molding material upon
molding. On the other hand, when the molding was conducted in the
granular state, the mold could not be successfully filled with the
molding material because the flowability of the molding material
was low. In addition, the portion filled with the molding material
contains a lot of voids, so that bleeding and separation of the
resin component was observed. The molding materials of Comparative
Examples 2, 4 and 5 contain no thixotropy-imparting agent. These
molding materials became clayish after the stirring, and so molding
itself could be conducted. However, the flowability of the resin
component was high, and surface roughness, which is considered to
be attributable to separation of the filler, was observed in the
molded articles. In addition, in Comparative Example 5, the mixed
amount of the wetting dispersant was large, and so a part of the
wetting dispersant was separated without acting on the filler.
The molding materials of Comparative Examples 3, 6, 7, 8 and 9
contain no wetting dispersant. In these Comparative Examples, the
resultant molding materials became granular like Comparative
Example 1. When the thixotropy-imparting agent was solid, the
molding material became powdery in Comparative Example 7 in which
the amount of the thixotropy-imparting agent added was large. When
the thixotropy-imparting agent was liquid, a part of the
thixotropy-imparting agent was separated without acting on the
filler in Comparative Example 9 in which the amount of the
thixotropy-imparting agent added was large. In Comparative Example
10, the resultant molding material became powdery because the epoxy
resin composition was solid, and the filler could not be completely
coated with the resin component upon molding.
Incidentally, with respect to the molding material of Example 4,
spiral flow was measured according to the testing method of molding
materials for sealing semiconductors in JAPAN ELECTRICAL
INSULLATING and ADVANCED PERFORMANCE MATERIALS INDUSTRIAL
ASSOCIATION (JEIA) Standards. The spiral flow was 81 cm (pressure:
6.9 MP) at 170.degree. C. and 79 cm (pressure: 6.9 MP) at
130.degree. C., so that the flowability of the molding material was
high even at a relatively low temperature. In addition, the molding
material according to this Example does not contain wax or an
organic metal salt as a pelletizing agent, a flowability improver
or an internal mold release agent. However, these components may
also be contained as needed to such an extent that they do not
elute out.
While the present invention has been described with reference to
exemplary embodiments, it is to be understood that the invention is
not limited to the disclosed exemplary embodiments. The scope of
the following claims is to be accorded the broadest interpretation
so as to encompass all such modifications and equivalent structures
and functions.
This application claims the benefit of Japanese Patent Application
No. 2014-088978, filed Apr. 23, 2014 which is hereby incorporated
by reference herein in its entirety.
* * * * *